Marine Parks are established to protect an area of the sea zoned as a sanctuary for the protection of its marine eco-systems, especially coral reefs and its associated fauna and flora, like sea grass beds, mangroves and the sea shores. In Malaysia, there are 6 marine parks to-date. Ironically, the establishment of marine parks also attracts more tourists to the areas. For example, the number of visitors to Payar Marine Park increased tremendously from 3,668 visitors in 1990 to 133,775 visitors in 2002. Environmentalists and scientists have voiced concern that too many tourists have adverse effects on the coral reefs. This study estimates how much visitors are willing to pay for two separate issues; first, to reduce the damages due to crowding effect and second, to reduce the damages due to inland development, of three marine parks in Malaysia; Payar, Redang and Tioman Marine Park. The willingness-to-pay estimates were obtained from the respondents using the Contingent Valuation Method. A total of 650 questionnaires were distributed to the respondents. Then, half of the total respondents were asked to answer the crowding effect issue, and the other half was asked the inland development issue. For the crowding effect issue the respondents were presented with a hypothetical situation in which the park authority wanted to reduce the damage to the corals by limiting the number of visitors to half the number who came in 2000. The reduction in the total number of visitors is to be achieved by imposing an increased entrance fee. For the inland development issue, an increase in the entrance fee is intended for the authority to hire more people to monitor and enforce rules, to treat sewage and to implement coastal zone management and planning. Estimation was done using the double-bounded dichotomous choice method. The willingness to pay (WTP) per person per visit to moderate the environmental impact of inland development is RM23.79, which is lower than the WTP to reduce crowding, RM31.59. In addition, when both data were combined to estimate the differences between the WTP of foreign and local visitors, we found that the WTP of foreign visitors was much higher than the WTP of locals at RM39.11 and RM19.52, respectively. Analyses using the Individual Travel Cost Method gave quite poor results since two thirds of the visitors were first-timers. Therefore, consumer surplus cannot be obtained due to the insignificant result of the respondent’s total spending on the number of trips. However, using the Zonal Travel Cost Method (ZTCM), the average consumer surplus was found to be the same, RM1,000 for each park. The ZTCM was also used to calculate the elasticity of demand. The results for the three marine parks were found not to vary much, ranging between 1.07 and 1.36.